Downey Municipal Code Ch. 7 Storm Water and Urban Runoff Pollution and Conveyance Controls

Except as specifically provided herein, any term used in this chapter shall be defined as provided in the most recent Los Angeles County National Pollutant Discharge Elimination System (NPDES) Municipal Separate Storm Sewer System (MS4) Permit, as this document may from time to time be amended and submitted to the Los Angeles Regional Water Quality Control Board (LARWQCB). If not defined in the current MS4 Permit, then such term shall be used as defined in the Federal Clean Water Act, as amended, or the regulations promulgated thereunder. If any definition contained in this chapter conflicts with the same term in the current MS4 Permit, then the definition contained in the current MS4 Permit shall govern. Any term used herein may be extended to include examples or cases identified elsewhere in Chapter 7 or as directed by the LARWQCB.

"Authorized Enforcement Officer"

means the "Director" or a City Code Enforcement Officer.

"Automotive Service Facility"

means a facility that is categorized with the Standard Industrial Classification (SIC) of 5013, 5014, 5511, 5541, 7532-7534 and 7536-7539 or equivalent North American Industry Classification System (NAICS) codes.

"Basin Plan"

means the Water Quality Control Plan, Los Angeles Region, Basin Plan for the Coastal Watersheds of Los Angeles and Ventura Counties, adopted by the Regional Water Board on June 13, 1994 and subsequent amendments.

"Best Management Practices" or "BMPs"

means practices or physical devices or systems designed to prevent or reduce pollutant loading from storm water or non-storm water discharges to receiving water, or designed to reduce the volume of storm water or non-storm water discharged to the receiving water.

"Biofiltration"

means a LID BMP that reduces stormwater pollutant discharges by intercepting rainfall on vegetative canopy, and through incidental infiltration and/or evapotranspiration, and filtration. Incidental infiltration is an important factor in achieving the required pollutant load reduction. Therefore, the term "biofiltration" as used in this chapter is defined to include only systems designed to facilitate incidental infiltration or achieve the equivalent pollutant reduction as biofiltration BMPs with an underdrain (subject to approval by the Regional Board's Executive Officer). Biofiltration BMPs include bioretention systems with an underdrain and bioswales.

"Bioretention"

means a LID BMP that reduces stormwater runoff by intercepting rainfall on vegetative canopy, and through evapotranspiration and infiltration. The bioretention system typically includes a minimum two-foot (2′) top layer of a specified soil and compost mixture underlain by a gravel-filled temporary storage pit dug into the in-situ soil. As defined in this chapter, a bioretention BMP may be designed with an overflow drain, but may not include an underdrain. When a bioretention BMP is designed or constructed with an underdrain it is regulated by Order No. R4-2012-0175 as biofiltration.

"Bioswale"

means a LID BMP consisting of a shallow channel lined with grass or other dense, low-growing vegetation. Bioswales are designed to collect stormwater runoff and to achieve a uniform sheet flow through the dense vegetation for a period of several minutes.

"California Regional Water Quality Control Board – Los Angeles Region" or "LARWQCB"

means the Board members, its Executive Officer, and their staff.

"Clean Water Act (CWA)"

means the Federal Water Pollution Control Act enacted in 1972, by Public Law 92-500, and amended by the Water Quality Act of 1987. The Clean Water Act prohibits the discharge of pollutants to waters of the United States unless the discharge is in accordance with an NPDES permit.

"Commercial Development"

means any development on private land that is not heavy industrial or residential. The category includes, but is not limited to: hospitals, laboratories and other medical facilities, educational institutions, recreational facilities, plant nurseries, car wash facilities; mini-malls and other business complexes, shopping malls, hotels, office buildings, public warehouses and other light industrial complexes (Order No. R4-2012-0175).

"Commercial Malls"

means any development on private land comprised of one or more buildings forming a complex of stores which sells various merchandise, with interconnecting walkways enabling visitors to easily walk from store to store, along with parking area(s). A commercial mall includes, but is not limited to: mini-malls, strip malls, other retail complexes, and enclosed shopping malls or shopping centers (Order No. R4-2012-0175).

"Construction Activity"

means any construction or demolition activity, clearing, grading, grubbing, or excavation or any other activity that results in land disturbance. Construction does not include emergency construction activities required to immediately protect public health and safety or routine maintenance activities required to maintain the integrity of structures by performing minor repair and restoration work, maintain the original line and grade, hydraulic capacity, or original purposes of the facility. See "Routine Maintenance" definition for further explanation. Where clearing, grading or excavating of underlying soil takes place during a repaving operation, State General Construction Permit coverage by the State of California General Permit for Storm Water Discharges Associated with Industrial Activities or for Stormwater Discharges Associated with Construction Activities is required if more than one acre is disturbed or the activities are part of a larger plan (Order No. R4-2012-0175).

"Construction/Industrial General Permit" or "CGP/IGP"

means the general NPDES permits adopted by the State Board, authorizing the discharge of storm water associated with construction or industrial activities respectively under certain conditions.

"Control"

means to minimize, reduce or eliminate by technological, legal, contractual, or other means, the discharge of pollutants from an activity or activities.

"Development"

means any construction, rehabilitation, redevelopment or reconstruction of any public or private residential project (whether single-family, multi-unit or planned unit development); industrial, commercial, retail and other non-residential projects, including public agency projects; or mass grading for future construction. It does not include routine maintenance to maintain original line and grade, hydraulic capacity, or original purpose of facility, nor does it include emergency construction activities required to immediately protect public health and safety.

"Directly Adjacent"

means situated within two hundred feet (200′) of the contiguous zone required for the continued maintenance, function, and structural stability of the environmentally sensitive area.

"Director"

means the Director of Public Works or designee(s).

"Discharge"

means any release, spill, leak, pump, flow, escape, dumping, or disposal of any liquid, semi-solid, or solid substance.

"Discharge of Pollutants"

shall mean any addition of "pollutant" or combination of pollutants to "waters of the United States" from any "point source" or, any addition of any pollutant or combination of pollutants to the waters of the "contiguous zone" of the ocean from any point source other than a vessel or other floating craft which is being used as a means of transportation. The term discharge includes additions of pollutants into waters of the United States from: surface runoff which is collected or channeled by man; discharges through pipes, sewers, or other conveyances owned by State, municipality, or other person which do not lead to a treatment works; and discharges through pipes, sewers, or other conveyances, leading into privately owned treatment works.

"Disturbed Area"

means an area that is altered as a result of clearing, grading, and/or excavation (Order No. R4-2012-0175).

"Downey Municipal Codes" or "DMC"

means the official governmental record of all regulatory, penal and certain administrative ordinances of the City of Downey, California, as it may be amended.

"Flow-Through Treatment BMPs"

means modular, vault type "high flow biotreatment" devices contained within an impervious vault with an underdrain or designed with an impervious liner and an underdrain.

"Full Capture System"

means any single device or series of devices, certified by the Executive Officer, that traps all particles retained by a five mm mesh screen and has a design treatment capacity of not less than the peak flow rate Q resulting from a one-year, one-hour storm in the sub-drainage area.

"Governmental"

means a municipal corporation, county, state, Federal, or governmental body, agency or entity.

"Green Roof"

means a LID BMP using planter boxes and vegetation to intercept rainfall on the roof surface. Rainfall is intercepted by vegetation leaves and through evapotranspiration. Green roofs may be designed as either a bioretention BMP or as a biofiltration BMP. To receive credit as a bioretention BMP, the green roof system planting medium shall be of sufficient depth to provide capacity within the pore space volume to contain the design storm depth and may not be designed or constructed with an underdrain.

"Hillside"

means a property located in an area with known erosive soil conditions, where the development contemplates grading on any natural slope that is 25% or greater and where grading contemplates cut or fill slopes.

"Illicit Connection"

means any man-made conveyance that is connected to the MS4 without a permit, excluding roof drains and other similar types of connections. Examples include channels, pipelines, conduits, inlets, or outlets that are connected directly to the storm drain system.

"Illicit Discharge"

means any discharge into the MS4 or from the MS4 into a receiving water that is prohibited under local, state, or Federal statutes, ordinances, codes, or regulations. The term illicit discharge includes any non-storm water discharge, except: authorized non-storm water discharges; conditionally exempt non-storm water discharges; and non-storm water discharges resulting from natural flows specifically identified in Part III.A.1.d of the MS4 Permit.

"Industrial/Commercial Facility"

means any facility involved and/or used in the production, manufacture, storage, transportation, distribution, exchange or sale of goods and/or commodities, and any facility involved and/or used in providing professional and non-professional services. This category of facilities includes, but is not limited to, any facility defined by either the Standard Industrial Classifications (SIC) or the North American Industry Classification System (NAICS). Facility ownership (Federal, state, municipal, private) and profit motive of the facility are not factors in this definition.

"Industrial Park"

means land development that is set aside for industrial development. Industrial parks are usually located close to transport facilities, especially where more than one transport modalities coincide: highways, railroads, airports, and navigable rivers. It includes office parks, which have offices and light industry.

"Infiltration BMP"

means a LID BMP that reduces stormwater runoff by capturing and infiltrating the runoff into in-situ soils or amended onsite soils. Examples of infiltration BMPs include infiltration basins, dry wells, and pervious pavement.

"Low Impact Development (LID)"

consists of building and landscape features designed to retain or filter stormwater runoff.

"Maximum Extent Practicable" or "MEP."

In selecting BMPs which will achieve MEP, it is important to remember that municipalities will be responsible to reduce the discharge of pollutants in storm water to the maximum extent practicable. This means choosing effective BMPs, and rejecting applicable BMPs only where other effective BMPs will serve the same purpose, the BMPs would not be technically feasible, or the cost would be prohibitive. The following factors may be useful to consider:

(1)

Effectiveness: Will the BMP address a pollutant of concern?

(2)

Regulatory compliance: Is the BMP in compliance with storm water regulations as well as other environmental regulations?

(3)

Public acceptance: Does the BMP have public support?

(4)

Cost: Will the cost of implementing the BMP have a reasonable relationship to the pollution control benefits to be achieved?

(5)

Technical feasibility: Is the BMP technically feasible considering soils, geography, water resources, etc.?

"MS4 Permit"

means the waste discharge requirement for municipal storm water and urban runoff discharges within the County of Los Angeles, and the incorporated cities therein, except the City of Long Beach issued by the LARWQCB. The provisions of this chapter shall be interpreted to provide legal authority to support applicable sections of subsequent LARWQCB MS4 Permit Orders, as they may apply within the City of Downey. Aspects of this chapter were developed based on discharge requirements contained in LARWQCB Orders 90-079, 96-054, 01-182, and R4-2012-0175.

"Municipal Separate Storm Sewer System" or "MS4"

means a conveyance or system of conveyances (including roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, manmade channels, or storm drains):

(1)

Owned or operated by a state, city, town, borough, county, parish, district, association, or other public body (created by or pursuant to State law) having jurisdiction over disposal of sewage, industrial wastes, storm water, or other wastes, including special districts under State law such as a sewer district, flood control district or drainage district, or similar entity, or an Indian tribe or an authorized Indian tribal organization, or a designated and approved management agency under section 208 of the Clean Water Act that discharges to waters of the United States; and

(2)

Designed or used for collecting or conveying storm water; and

(3)

Which is not a combined sewer; and

(4)

Which is not part of a publicly owned treatment works (POTW) as defined at 40 CFR Section 122.26(b)(8).

"National Pollutant Discharge Elimination System" or "NPDES"

means the national program for issuing, modifying, revoking and reissuing, terminating, monitoring and enforcing permits, and imposing and enforcing pretreatment requirements, under Clean Water Act Sections 307, 402, 318 and 405, as amended. This term includes an "approved program."

"Natural Drainage System"

means a drainage system that has not been improved (e.g., channelized or armored). The clearing or dredging of a natural drainage system does not cause the system to be classified as an improved drainage system.

"New Development"

means land disturbing activities, structural development, including construction or installation of a building or structure, creation of impervious surfaces, and land subdivision.

"Non-Storm Water Discharge"

means any discharge to a municipal storm drain system that is not composed entirely of storm water.

"Outfall"

means a point source as defined by 40 CFR Section 122.2 at the point where a municipal separate storm sewer discharges to waters of the United States and does not include open conveyances connecting two municipal separate storm sewers, or pipes, tunnels or other conveyances with connect segments of the same stream or other waters of the United States and are used to convey waters of the United States. (40 CFR Section 122.26(b)(9).)

"Owner"

means the legal owner of a parcel of real property, except when the legal owner of the property is the holder of the mortgage, note, or other such security, in which case it is beneficiary of said real property.

"Parcel"

means the smallest lot, unit or plot of land having an owner, boundaries, surface area and Los Angeles County Tax Assessor Number.

"Parking Lot"

means land area or facility for the parking or storage of motor vehicles used for businesses, commerce, industry, or personal use, with a lot size of 5,000 square feet or more of surface area, or with 25 or more parking spaces.

"Planning Priority Projects"

means those new development and redevelopment projects that are required by the MS4 Permit to incorporate appropriate storm water mitigation measures into their design plan.

"Pollutant(s)"

means any "pollutant" defined in Section 502(6) of the Federal Clean Water Act or incorporated into the California Water Code Section 13373.

"Project"

means all development, redevelopment, and land disturbing activities. The term is not limited to "Project" as defined under CEQA (Public Resources Code Section 21065).

"Rainfall Harvest and Use"

means a LID BMP system designed to capture runoff, typically from a roof but can also include runoff capture from elsewhere within the site, and to provide for temporary storage until the harvested water can be used for irrigation or non-potable uses. The harvested water may also be used for potable water uses if the system includes disinfection treatment and is approved for such use by the local building department and other necessary local, state, and Federal agencies as required.

"Receiving Water"

means "water of the United States" into which waste and/or pollutants are or may be discharged.

"Redevelopment"

means any construction activity that results in the creation, addition, or replacement of 5,000 square feet or more of impervious surface area on an already developed site. Redevelopment includes, but is not limited to: the expansion of a building footprint; addition or replacement of a structure; replacement of impervious surface area that is not part of a routine maintenance activity; and land-disturbing activities related to structural or impervious surfaces. Redevelopment does not include routine maintenance activities to maintain original line and grade, hydraulic capacity, original purpose of facility or emergency construction activities to immediately protect public health and safety.

"Regional Board"

means the California Regional Water Quality Control Board, Los Angeles Region.

"Restaurant"

means a facility that sells prepared foods and drinks for consumption, including stationary lunch counters and refreshment stands selling prepared foods and drinks for immediate consumption (SIC Code 5812).

"Retail Gasoline Outlet"

means any facility engaged in selling gasoline and lubricating oils.

"Routine Maintenance"

includes, but is not limited to, projects conducted to:

(1)

Maintain the original line and grade, hydraulic capacity, or original purpose of the facility.

(2)

Perform as needed restoration work to preserve the original design grade, integrity and hydraulic capacity of flood control facilities.

(3)

Includes road shoulder work, regrading dirt or gravel roadways and shoulders and performing ditch cleanouts.

(4)

Update existing lines* and facilities to comply with applicable codes, standards, and regulations regardless if such projects result in increased capacity.

(5)

Repair leaks.

Routine maintenance does not include construction of new** lines or facilities resulting from compliance with applicable codes, standards and regulations.

"Runoff"

means any runoff including storm water and dry weather flows from a drainage area that reaches a receiving water body or subsurface. During dry weather it is typically comprised of base flow either contaminated with pollutants or uncontaminated, and nuisance flows.

"Significant Ecological Areas (SEAs)"

means an area that is determined to possess an example of biotic resources that cumulatively represent biological diversity, for the purposes of protecting biotic diversity, as part of the Los Angeles County General Plan. Areas are designated as SEAs, if they possess one or more of the following criteria:

(1)

The habitat of rare, endangered, and threatened plant and animal species.

(2)

Biotic communities, vegetative associations, and habitat of plant and animal species that are either one of a kind, or are restricted in distribution on a regional basis.

(3)

Biotic communities, vegetative associations, and habitat of plant and animal species that are either one of a kind or are restricted in distribution in Los Angeles County.

(4)

Habitat that at some point in the life cycle of a species or group of species, serves as a concentrated breeding, feeding, resting, migrating grounds and is limited in availability either regionally or within Los Angeles County.

(5)

Biotic resources that are of scientific interest because they are either an extreme in physical/geographical limitations, or represent an unusual variation in a population or community.

(6)

Areas important as game species habitat or as fisheries.

(7)

Areas that would provide for the preservation of relatively undisturbed examples of natural biotic communities in Los Angeles County.

(8)

Special areas.

"Site"

means land or water area where any "facility or activity" is physically located or conducted, including adjacent land used in connection with the facility or activity.

"Standard Industrial Classification" or "SIC"

means the four digit code system used to identify business types in the MS4 Permit and Clean Water Act Amendments. The six digit North American Industrial Classification System (NAICS) is supplanting the SIC. Cross-references between SIC and NAICS codes shall follow those of the Economic Classification Policy Committee of the United States Office of Management and Budget, which is distributed by the National Technical Information Service.

"Storm Drain System"

means any facility or any parts of the facility, including streets, gutters, conduits, natural or artificial drains, channels and watercourse that are used for the purpose of collecting, storing, transporting or disposing of storm water and are located within the City.

"Storm Water"

means storm water runoff, snow melt runoff, and surface runoff and drainage related to precipitation events.

"Storm Water Pollution Prevention Plan" or "SWPPP"

means a plan, as required by the State Construction General and Industrial General Permits identifying potential pollutant sources and describing the design, placement, and implementation of BMPs, to effectively prevent non-stormwater discharges and reduce pollutants in stormwater discharges during activities covered by these permits.

"Structural BMP"

means any structural facility designed and constructed to mitigate the adverse impacts of storm water and urban runoff pollution, including source control and treatment control BMPs.

"Treatment Control BMP"

means any engineered system designed to remove pollutants by simple gravity settling of particulate pollutants, filtration, biological uptake, media adsorption or any other physical, biological or chemical process.

"Urban Runoff"

means surface water flow produced by storm and non-storm events. Non-storm events include flow from residential, commercial or industrial activities involving the use of potable and non-potable water.

"Urban Runoff Mitigation Plan"

means an appropriate LID, SUSMP, or Site Specific Mitigation Plan.

"Watershed Management Program"

means the City's stormwater program to implement the requirements of the NPDES MS4 Permit.

(Added by Ord. 1036, adopted 01-28-97; amended by Ord. 1130, adopted 08-27-02; Ord. 1142, adopted 02-11-03; Ord. 1320, adopted 11-12-13; Ord. 14-1330, adopted 4-22-14)

Notwithstanding other provisions in the Downey Municipal Codes, the MS4 Permit requires the City of Downey to implement the Watershed Management Program (WMP) as an enforceable element of the permit. Applicable program elements set forth in the WMP, and any subsequent amendments, are hereby incorporated into this chapter by reference.

(Added by Ord. 1142, adopted 02-11-03; amended by Ord. 1320, adopted 11-12-13; Ord. 14-1330, adopted 4-22-14)

(a) Pollutant(s) prohibited from discharge to the MS4 shall include:

(1) Any water constituent found at concentrations or levels that may potentially cause a beneficial use impairment in a downstream receiving water body that has been nominated or is currently on, a LARWQCB 303(d), Monitoring, Enforceable Limit, or similar list;

(2) Any sediment, settleable, or suspended solid;

(3) Any living or dead animal or their biological waste products;

(4) Any food, food processing or medical waste;

(5) Any thermal, color, conductive, oxygen demanding, growth inducing, corrosive, or radioactive waste;

(6) Any chemical waste, salt, organic compound, pesticide, or metal;

(7) Any hydrocarbon based fuel, oil, lubricant, fluid, or additive; and

(8) Any substance designated as a pollutant by the LARWQCB.

(Added by Ord. 1036, adopted 01-28-97; amended by Ord. 1142, adopted 02-11-03; Ord. 1320, adopted 11-12-13; Ord. 14-1330, adopted 4-22-14)

(a) No owner, responsible party, or person, shall use, allow, or suffer, an illicit connection to the MS4; and must therefore remove or terminate such illicit connection.

(b) No person or responsible party shall cause, nor contribute, to the exceedance of water quality standards, nor impair attainable beneficial use objectives in receiving waters of the State.

(c) All non-storm water discharges are prohibited unless they're identified in Part III.A of the MS4 Permit. A discharge may be exempt or conditionally exempt if:

(1) It consists entirely of storm water; or

(2) It is authorized by an NPDES permit; or

(3) It is identified in Part III.A of the MS4 Permit; or

(4) It is authorized by the Executive Officer of the LARWQCB.

(d) Illicit discharges that are prohibited from entering the MS4 shall include, but are not limited to, the following:

(1) The discharge of wash waters to the MS4 from the cleaning of gas stations, auto repair garages, or other automotive service facilities;

(2) The discharge of runoff to the MS4 from mobile auto washing, steam cleaning, mobile carpet cleaning, and other such mobile commercial and industrial operations;

(3) The discharge of runoff to the MS4 from areas where repair of machinery and equipment, which are visibly leaking oil, fluid or antifreeze, is undertaken;

(4) The discharge of runoff or wash down to the MS4 from paved or unpaved storage areas where materials containing grease, oil, paint, toxic or other hazardous substances, and uncovered receptacles containing hazardous materials are, or have been, located;

(5) The discharge of chlorinated or brominated, swimming pool or spa water and filter backwash or diatomaceous earth to the MS4;

(6) The washing of materials or impervious surfaces that result in discharges to the MS4;

(7) The discharge of concrete or cement laden wash water from concrete trucks, pumps, tools, and equipment to the MS4; and

(8) Dumping or disposal of materials into the MS4, other than storm water, such as:

(i) Solid waste as defined in California Public Resources Code, Section 40191;

(ii) Solid waste, including, but not limited to, trash, litter, food wastes, packaging, paper bags, newspaper, and garbage;

(iii) Construction or landscape debris, such as leaves, dirt, grass clippings, bark, fertilizer, bags, plant cans or bedding packs;

(iv) Any governmentally banned or unregistered pesticide, insecticide, fungicide, nematicide, acaricide, or herbicide;

(v) Automotive, fuel and chemical wastes including batteries;

(vi) Animal, biological, food processing, or medical wastes; and

(vii) Other material that may have an adverse impact on water quality, wildlife, or receiving water habitat value.

(Added by Ord. 1036, adopted 01-28-97; amended by Ord. 1142, adopted 02-11-03; Ord. 1320, adopted 11-12-13; Ord. 14-1330, adopted 4-22-14)

(a) It shall be a violation of this chapter for any person or entity, required by governmental law to obtain a NPDES stormwater activities permit, to conduct a construction, commercial, or industrial activity in the City of Downey, without the appropriate Construction General Permit (CGP) or Industrial General Permit (IGP).

(b) Any person or entity, required to have an NPDES stormwater activities permit for a parcel within the City of Downey, shall retain at said parcel the following evidence of compliance with the CGP or IGP and make said documents available upon request from an Authorized Enforcement Officer: (1) a copy of the submitted Notice of Intent (NOI) to comply with State Stormwater Waste Discharge Requirements or a waste discharge identification (WDID) number issued by the SWRCB; (2) a SWPPP; and (3) site specific storm water quality data.

(c) Any person or entity in the City of Downey requiring a CGP or IGP for facilities under their control or operation, shall characterize the adequacy of the facility SWPPP in applying source and treatment control BMPs to at least the MEP standard and comply with the requirements of the SWPPP.

(d) No person or entity shall obfuscate or otherwise attempt to conceal the nature or operation of a construction, commercial, or industrial site, or facility, in order to avoid obtaining the appropriate governmental stormwater permits.

(e) Industrial and construction facilities not subject to the IGP and CGP that are subject to pollution control requirements under the municipal NPDES permit shall implement BMPs prescribed by the regional board or its executive officer, through programs or actions made pursuant to the municipal NPDES permit.

(Added by Ord. 1036, adopted 01-28-97; amended by Ord. 1142, adopted 02-11-03; Ord. 1320, adopted 11-12-13; Ord. 14-1330, adopted 4-22-14)

The owner, occupant or other person in charge of day-to-day operation or maintenance of each parcel within the City of Downey shall adhere to the following BMP requirements in order to prevent or reduce the discharge of pollutants to achieve water quality standards/receiving water limitations:

(a) For premises exposed to storm water, the owner, occupant or other person in charge of day-to-day operations shall use appropriate BMPs, or other steps to reduce the discharge of pollutants to at least the MEP standard.

(b) No person or entity shall dump, release, spill, leak, pump, pour, emit, empty, discharge, inject, bury or dispose into the environment, any solid or liquid wastes, including any pollutant, in or upon any part of MS4, or upon any public or private premises in the City of Downey.

(c) No person or entity shall cause, suffer, or permit any solid or liquid waste or pollutant, to come to be located upon, in, on, or under any premises in the City of Downey, except in the original manufacturer's container or a governmentally authorized container, waste facility, or treatment works.

(d) No person shall dispose of any hazardous substance or material, into any litter or waste container, without the written authorization of the site or container, owner or operator.

(e) Water used for irrigation purposes shall not be allowed to run off of a site.

(f) Washing down paved areas shall be prohibited unless it conforms to the definition of sidewalk rinsing given in the MS4 Permit. If necessary for health or safety purposes, and not in violation of any other provision of this Code, then washing down paved areas is authorized when all applicable BMP measures are implemented to remove pollutants, or if the resulting wastewater is collected and discharged to a sanitary sewer.

(g) Uncovered outdoor storage of unsealed containers of building materials, lawn and automotive care products, or other substances that may contribute pollutants to the storm water conveyance system, is prohibited.

(h) Commercial tenants, multi-family building managers and industrial owners shall inspect trash receptacles and refuse storage areas on a weekly basis for loose garbage and liquid waste residue and shall not allow such garbage and residue to enter the storm drain system. Trash receptacles shall be maintained with solid unbroken closed covers to prevent the entry of rain, or exit of wind-blown or animal-strewn litter and leaking fluids.

(i) Premises with 25 or more motor vehicle parking spaces, or 5,000 square feet of parking lot area, and upon which runoff water is conveyed, shall be vacuum swept monthly and shall employ other BMPs as may be necessary, to reduce discharges to the MEP.

(j) Premises with between 10 and 24 motor vehicle parking spaces, and upon which runoff water is conveyed, shall be vacuum swept quarterly and shall employ other BMPs as may be necessary, to reduce discharges to the MEP.

(k) For premises where machinery or other equipment is repaired or maintained, the owner, occupant or other person in charge of the day-to-day operations shall use BMPs or other steps to prevent discharge of maintenance or repair related pollutants to the MS4.

(l) Materials and equipment necessary for pollutant source control activities, that are commensurate with facility operations and materials, shall be maintained and kept readily available and accessible to all employees.

(m) Any BMP, runoff reduction, discharge control structure, or activity must be designed, operated and maintained to prevent the release of odors, or entrance and proliferation of pathogens or their vectors, or other nuisance microbe, invertebrate or vertebrate organisms.

(n) If the Director determines that water quality criteria may be compromised by discharges from a parcel or development, the Director shall have the authority to require BMP implementation until the discharge of runoff or pollutants to the MS4, or receiving water, have been reduced to the MEP.

(Added by Ord. 1036, adopted 01-28-97; amended by Ord. 1142, adopted 02-11-03; Ord. 1320, adopted 11-12-13; Ord. 14-1330, adopted 4-22-14)

(a) The following pollution source control requirements shall apply to all persons submitting applications for new development or redevelopment projects within the City of Downey.

(1) During application review for new development or redevelopment projects, the applicant shall submit an appropriate project specific Urban Runoff Mitigation Plan to the Director.

(2) Structural and design elements that typically increase infiltration, reduce pollutant conveyance, and decrease runoff include:

(i) Using landscaped/vegetated areas, sand filters, swales, infiltration basins, biofilters, and planters to maximize infiltration;

(ii) Replacing impermeable surfaces with porous materials;

(iii) Directing impervious surface runoff to permeable areas;

(iv) Grading the site to encourage runoff to permeable areas;

(v) Directing runoff to dry wells, perforated pipes, infiltration trenches, or other source reduction BMPs;

(vi) Designing curbs and landscaping to facilitate infiltration;

(vii) Using cisterns or retention basins to store precipitation; and

(viii) Installing treatment control BMPs to remove pollutants.

(3) All Urban Runoff Mitigation Plans must include a structural and treatment control BMP maintenance schedule, the applicant's signed statement of responsibility for continued BMP maintenance, and plan for continued maintenance responsibilities.

(4) The applicant shall retain responsibility for such maintenance until responsibility is legally transferred in accordance with this chapter.

(5) Applicant, facility operators and/or owners shall also provide, as requested by the Director, any other legally enforceable agreement that assigns responsibility for the maintenance of post-construction structural or treatment control BMPs.

(6) The Urban Runoff Mitigation Plan must indicate that subsequent property transfers include, as a written condition and are subject to, the transferee assuming full responsibility for maintenance of any structural, treatment and/or source control BMPs.

(7) As a condition for issuing a certificate of occupancy for a new development or redevelopment project, the Director shall require the applicant, facility operators and/or owners, as appropriate, to construct all storm water pollution control BMPs and structural or treatment control BMPs shown on the approved project plans.

(8) As a condition for issuing a certificate of occupancy for a new development or redevelopment project, the Director shall require the applicant, facility operators and/or owners to submit, for review and approval, a BMP maintenance schedule and inspection plan.

(9) As a condition for issuing a certificate of occupancy for a new development or redevelopment project, the Director shall require that the applicant file a signed statement that the project site and all structural or treatment control BMPs shall be maintained in compliance with the Urban Runoff Mitigation Plan.

(Added by Ord. 1036, adopted 01-28-97; amended by Ord. 1142, adopted 02-11-03; amended by Ord. 1320, adopted 11-12-13; Ord. 14-1330, adopted 4-22-14)

(a) The following design elements shall be required for all new development or redevelopment projects, except single-family residences:

(1) Preparation and Director approval of the Urban Runoff Mitigation Plan, as a condition of Planning or Building Department approval.

(2) Runoff shall not be conveyed to, or through, the following areas:

(i) Loading and unloading dock areas;

(ii) Repair and maintenance bays; and

(iii) Vehicle and equipment wash and fueling areas.

(3) Developments which include outdoor material storage areas that may discharge MS4 pollutants, must include design elements to:

(i) Place the materials within enclosures, such as cabinets, sheds, or awnings, which prevent contact with rain, runoff, or other liquids that might flow to the MS4.

(ii) Liquid handling areas shall use impervious spill containing floors, drains, sumps, vessels, berms, dikes, and curbs to contain materials and eliminate discharges to the MS4.

(4) Waste material bins with a capacity greater than 1/4 cubic yard (or 50 gallons) must be stored in a covered area to prevent rainfall or roof drainage, from any structure, through the waste.

(5) Any project including down spouts, roof gutters or subsurface drainage shall utilize perforated pipe in approved infiltration areas, infiltration trenches, "French drain" or similar systems, unless prohibited by the Director.

(6) Each Urban Runoff Management Plan shall be individually evaluated to ascertain whether the proposed project and site characteristics meet governmental standards.

(7) The Urban Runoff Mitigation Plan must demonstrate to the Director's satisfaction that proposed BMPs, numeric design criteria, or design elements meet the requirements of this chapter.

(8) The Director shall approve or disapprove of any proposed project plans. If the plans are disapproved, the developer may request a written explanation for the disapproval. No city grading or building permit shall be issued until the Director has approved an Urban Runoff Mitigation Plan.

(b) Development projects subject to permittee permitting and approval for the design and implementation of post-construction controls to mitigate storm water pollution, prior to completion of the project(s), are:

(1) All development projects equal to one acre or greater of disturbed area that adds more than 10,000 square feet of impervious surface area.

(2) Industrial parks 10,000 square feet or more of surface area.

(3) Commercial malls 10,000 square feet or more of surface area.

(4) Retail gasoline outlets with 5,000 square feet or more of surface area.

(5) Restaurants (Standard Industrial Classification (SIC) of 5812) with 5,000 square feet or more of surface area.

(6) Parking lots with 5,000 square feet or more of impervious surface area, or with 25 or more parking spaces.

(7) Streets and roads construction of 10,000 square feet or more of impervious surface area. Street and road construction applies to standalone streets, roads, highways, and freeway projects, and also applies to streets within larger projects. Specific requirements in subsection (c)(2).

(8) Automotive service facilities (Standard Industrial Classification (SIC) of 5013, 5014, 5511, 5541, 7532-7534 and 7536-7539) 5,000 square feet or more of surface area.

(9) Projects located in or directly adjacent to, or discharging directly to an environmentally sensitive area (ESA), where the development will:

(i) Discharge storm water runoff that is likely to impact a sensitive biological species or habitat; and

(ii) Create 2,500 square feet or more of impervious surface area.

(10) Single-family hillside homes.

(11) Redevelopment Projects.

(i) Land disturbing activity that results in the creation or addition or replacement of 5,000 square feet or more of impervious surface area on an already developed site on planning priority project categories.

(ii) Where redevelopment results in an alteration to more than 50% of impervious surfaces of a previously existing development, and the existing development was not subject to post-construction stormwater quality control requirements, the entire project must be mitigated.

(iii) Where redevelopment results in an alteration of less than 50% of impervious surfaces of a previously existing development, and the existing development was not subject to post-construction stormwater quality control requirements, only the alteration must be mitigated, and not the entire development.

(iv) Redevelopment does not include routine maintenance activities that are conducted to maintain original line and grade, hydraulic capacity, original purpose of facility or emergency redevelopment activity required to protect public health and safety. Impervious surface replacement, such as the reconstruction of parking lots and roadways which does not disturb additional area and maintains the original grade and alignment, is considered a routine maintenance activity. Redevelopment does not include the repaving of existing roads to maintain original line and grade.

(c) Specific Requirements. The site for every planning priority project shall be designed to control pollutants, pollutant loads, and runoff volume to the maximum extent feasible by minimizing impervious surface area and controlling runoff from impervious surfaces through infiltration, evapotranspiration, bioretention and/or rainfall harvest and use.

(1) A new single-family hillside home development shall include mitigation measures to:

(i) Conserve natural areas;

(ii) Protect slopes and channels;

(iii) Provide storm drain system stenciling and signage;

(iv) Divert roof runoff to vegetated areas before discharge unless the diversion would result in slope instability; and

(v) Direct surface flow to vegetated areas before discharge, unless the diversion would result in slope instability.

(2) Street and road construction of 10,000 square feet or more of impervious surface shall follow USEPA guidance regarding Managing Wet Weather with Green Infrastructure: Green Streets (December 2008 EPA-833-F-08-009) or similar guidance manual to the maximum extent practicable.

(3) The remainder of planning priority projects shall prepare a LID plan to comply with the following:

(i) Retain stormwater runoff on-site for the Stormwater Quality Design Volume (SWQDv) defined as the runoff from:

A. The 85th percentile 24-hour runoff event as determined from the Los Angeles County 85th percentile precipitation isohyetal map; or

B. The volume of runoff produced from a 0.75 inch, 24-hour rain event, whichever is greater.

(ii) Minimize hydromodification impacts to natural drainage systems as defined in Order No. R4-2012-0175.

(iii) To demonstrate technical infeasibility, the project applicant must demonstrate that the project cannot reliably retain 100% of the SWQDv on-site, even with the maximum application of green roofs and rainwater harvest and use, and that compliance with the applicable post-construction requirements would be technically infeasible by submitting a site-specific hydrologic and/or design analysis conducted and endorsed by a registered professional engineer, geologist, architect, and/or landscape architect. Technical infeasibility may result from conditions including the following:

A. The infiltration rate of saturated in-situ soils is less than 0.3 inch per hour and it is not technically feasible to amend the in-situ soils to attain an infiltration rate necessary to achieve reliable performance of infiltration or bioretention BMPs in retaining the SWQDv on-site;

B. Locations where seasonal high groundwater is within five feet to 10 feet of surface grade;

C. Locations within 100 feet of a groundwater well used for drinking water;

D. Brownfield development sites or other locations where pollutant mobilization is a documented concern;

E. Locations with potential geotechnical hazards;

F. Smart growth and infill or redevelopment locations where the density and/or nature of the project would create significant difficulty for compliance with the on-site volume retention requirement.

(iv) If partial or complete on-site retention is technically infeasible, the project site may biofiltrate one and one-half times the portion of the remaining SWQDv that is not reliably retained on-site. Biofiltration BMPs must adhere to the design specifications provided in Order No. R4-2012-0175.

A. Additional alternative compliance options such as off-site infiltration and groundwater replenishment projects may be available to the project site. The project site should contact the Department of Public Works to determine eligibility.

(v) The remaining SWQDv that cannot be retained or biofiltered on-site must be treated on-site to reduce pollutant loading. BMPs must be selected and designed to meet pollutant-specific benchmarks as required per Order No. R4-2012-0175. Flow-through BMPs may be used to treat the remaining SWQDv and must be sized based on a rainfall intensity of:

A. Two tenths inch per hour; or

B. The one year, one hour rainfall intensity as determined from the most recent Los Angeles County isohyetal map, whichever is greater.

(d) Additional Requirements. The site for projects not classified with general applicability listed in subsection (b) of this section, but resulting in the creation or addition or replacement of 800 square feet or more of impervious surface area shall be designed to control pollutants, pollutant loads, and runoff volume as approved by the City.

(Added by Ord. 1036, adopted 01-28-97; amended by Ord. 1142, adopted 02-11-03; Ord. 1320, adopted 11-12-13; Ord. 14-1330, adopted 4-22-14)

(Added by Ord. 1095, adopted 01-23-01; amended by Ord. 1130, adopted 08-27-02; repealed by Ord. 1142, adopted 02-11-03)

The following urban runoff reduction requirements shall apply to all persons submitting applications for new development or redevelopment projects within the City of Downey:

(a) New development and redevelopment projects within the City of Downey are required to prepare current condition and post proposed development hydrology studies based on current Los Angeles County Department of Public Works Design Storm and Hydrology methods.

(b) Where proposed development is expected to generate higher peak runoff flows, as compared to that which currently exists, the Director shall require reasonable drainage improvements within the lot, or public right-of-way, to accommodate the potential effect of such additional water flows.

(c) Where such proposed development may affect the existing flow of water, the flow of water in natural drainage courses, or within streets or other public rights-of-way, the Director shall require reasonable drainage improvements within the lot, water course, or public right-of-way, to accommodate the potential effect of such additional water flows.

(Added by Ord. 1036, adopted 01-28-97; amended by Ord. 1142, adopted 02-11-03; Ord. 1320, adopted 11-12-13; Ord. 14-1330, adopted 4-22-14)

The transfer, sale, deed, or lease of a parcel, which is subject to a requirement for maintenance of structural and treatment control BMPs shall include conditions requiring and assigning the transferee, and its successors, to:

(a) Assume responsibility for maintenance and operation of any existing structural or treatment control BMP to at least MEP standard.

(b) Replace any degraded structural or treatment control BMP with new control measures or BMPs meeting the then current standards of the City.

(c) Conduct BMP maintenance and inspections as required in the approved Low Impact Development (LID) Plan, Urban Runoff Mitigation Plan, or the LID ordinance.

(d) Insure that all structural or treatment control BMPs are inspected at least yearly and retain proof of such inspections for at least three years.

(e) For conditions, covenants and restrictions for properties which include structural or treatment control BMPs that are to be maintained by a homeowner's association, such conditions, covenants and restrictions shall provide for maintenance of the BMPs by the association.

(f) BMPs that are to be maintained by individual property owners, shall include a written explanation of the maintenance responsibilities with any deed transferring title to said property, as well as being attached to any property conditions, covenants and restrictions.

(g) If property, on which structural or treatment control BMPs are located, is to be dedicated to a governmental agency, the transferor shall remain responsible for the BMPs until the agency provides a signed assumption of responsibility and conformation that they meet agency design standards.

(h) All structural BMPs are required to be properly operated and maintained according to product specifications and site characteristics to maintain effectiveness in reducing the discharge of pollutants. Documentation on operation and maintenance activities shall be retained on-site at all times, and made available upon request by an authorized enforcement officer.

(Added by Ord. 1036, adopted 01-28-97; amended by Ord. 1142, adopted 02-11-03; Ord. 1320, adopted 11-12-13; Ord. 14-1330, adopted 4-22-14)

Persons, and entities, discharging runoff or pollutants are made accountable for their actions through the mechanisms in this section.

(a) Discharges to the MS4 are required to comply with the provisions and conditions of this chapter and applicable Federal, State or LARWQCB permits, orders, contracts, model programs, or plans.

(b) Each of the following is hereby determined to be a threat to the public health, safety and welfare, and is declared and deemed a public nuisance, which may be abated or restored by any Authorized Enforcement Officer. A civil or criminal action to abate, enjoin or otherwise compel the cessation of such nuisance may be brought by the City Attorney, pursuant to the City's authority to abate nuisances:

(1) Any condition caused or permitted to exist in violation of any of the provisions of this chapter; or

(2) Any failure to comply with applicable requirements of an approved LID Plan, Urban Runoff Mitigation Plan, or LID ordinance with respect to a property; or

(3) Any failure to comply with any applicable requirement of a contract to which the City is a party; or

(4) Any failure to comply with any applicable order or notice issued pursuant to this section; or

(5) Any false certification or verification; or

(6) Any failure to comply with a certification or verification provided by a project applicant or the applicant's successor in interest; or

(7) Any failure to properly operate and maintain any structural or treatment control BMP in accordance with an approved LID Plan, Urban Runoff Mitigation Plan, or LID ordinance.

(c) The cost of nuisance abatement as provided in subsection (b), shall be borne by the property owner from which the discharge originated and the cost shall be assessed to that owner, pursuant to the procedure for cost recovery set forth in Chapter 2 of Article V of the DMC.

(d) If any violation of this chapter constitutes a seasonal or recurrent nuisance, the Director shall so declare. The failure of any person to take appropriate annual precautions to prevent such pollution, after written notice of a determination under this subsection, shall constitute a public nuisance and a violation of this chapter.

(e) Causing, permitting, aiding, abetting, or concealing a violation of any provision of this chapter shall constitute a violation of this chapter.

(f) In addition to other remedies in this section, violations of this chapter may be enforced by civil action brought by the City. During such action, the City may seek, as appropriate, any or all of the following remedies:

(1) A temporary or permanent injunction;

(2) Assessment upon the owner or violator of any investigation, inspection, or monitoring costs, which led to the establishment of the violation, and for the reasonable costs of preparing and bringing legal action under this subsection;

(3) Costs incurred in removing, correcting, or terminating the adverse effects resulting from violation;

(4) Compensatory damages for loss or destruction to water quality, wildlife, fish and aquatic life.

(g) When an Authorized Enforcement Officer finds that a discharge has taken or may take place in violation of this chapter, the officer may issue an order to cease and desist said practice or operation causing, or likely to cause, such discharge. The Authorized Enforcement Officer may then direct that those persons not complying shall:

(1) Comply with the requirement;

(2) Comply with a time schedule for compliance; and

(3) Take appropriate remedial or preventive action to prevent the violation from recurring.

(h) Whenever an Authorized Enforcement Officer finds any pollutant upon any right-of-way, land, or ground adjoining an adjacent parcel, the officer may give notice to the owner of the adjacent property to remove such pollutant in any reasonable manner. The recipient of such notice shall undertake the activities as described in the notice.

(i) Violation of this chapter shall be punishable as a misdemeanor as provided in Chapter 2 of Article 1 of this Code. Each day that a violation continues shall constitute a separate offense.

(j) To the extent the City makes compliance with this chapter, or any provision of this chapter, a condition of approval to the issuance of a permit or license, any person in violation of such condition is subject to the permit revocation procedures set forth elsewhere in this Code.

(k) Remedies contained within this chapter are in addition to, and do not supersede or limit, any and all other remedies, whether they be civil or criminal. The remedies provided for in this chapter shall be cumulative and not exclusive.

(l) Whenever necessary, interagency coordination will be employed to enforce the provisions of this chapter.

(Added by Ord. 1036, adopted 01-28-97; amended by Ord. 1142, adopted 02-11-03; Ord. 1320, adopted 11-12-13; Ord. 14-1330, adopted 4-22-14)

Whenever necessary to make an inspection to enforce any provisions of this chapter, an Authorized Enforcement Officer may enter any property in the City of Downey in a manner authorized by State law. The inspection authority pursuant to this Section shall include the authority to enter, sample, inspect, review records, copy records, and require regular reports from industrial, commercial and construction facilities and sites, with the potential to discharge pollution to the MS4.

(Added by Ord. 1036, adopted 01-28-97; amended by Ord. 1142, adopted 02-11-03; Ord. 1320, adopted 11-12-13; Ord. 14-1330, adopted 4-22-14)

The City Council may establish fees for the services provided under this chapter and such fees may be adjusted from time to time by City Council Resolution.

(Added by Ord. 1036, adopted 01-28-97; amended by Ord. 1142, adopted 02-11-03; Ord. 1320, adopted 11-12-13; Ord. 14-1330, adopted 4-22-14)